It is conventional that the control of the variables describing the driving dynamics, such as sideslip angle, angular velocity of sideslip, and/or yaw rate, allows an improved vehicle stability to be attained. In this context, these values cannot be acted upon directly, but rather the performance can only be controlled indirectly with the aid of control variables. Possible control variables for intervening in the driving dynamics include, for example, steering angle, braking forces, and/or spring stiffnesses of the wheel suspensions.
In particular, in the case of so-called steer-by-wire systems, the connection between the steering wheel and steering intervention is separated at the axles. Such a separation allows automatic corrections of the steering-wheel inputs of the driver for steering intervention at the axles.
Thus, it is described, for example, in U.S. Pat. No. 4,706,771 that one can intervene in the driving dynamics via the front-axle and/or rear-axle steering systems. The control-variable setpoint for the steering intervention is calculated on the basis of a setpoint yaw behavior and/or a setpoint sideslip angle, in light of a vehicle model for a stationary driving state determined by the driving speed and the desired steering. The stationary driving state is the driving state, which may be determined for a vehicle at an operating point defined on the basis of a driving speed and/or a curve radius. Such precontrol does not allow a rapid reaction to driving conditions that change due to, e.g. a change of roadway pavement.
It is an object of the present invention to provide a method and a device for robustly controlling the driving dynamics, using steering actions at at least one axle, which may allow a rapid reaction to dynamic changes in driving conditions.